All in sundry

[ericthered]

I figure this is the right place to post since I have questions, first. I am interested in building a steam engine and a gasoline engine, both I wouldn't build until I have a shop (best case scenario a year trying to sell a place right now). anyway, I was going to cast both, both would be full size (the gasoline to power a ultralight helicopter and the steam to power a generator.
First one would be the gas one, I figured a 4 or 6 cyl aircooled that would need to crank out 40-60 HP, Question: how would I design a engine around output rating? I figured that I would use a production line engine bore so that I wouldn't have to make the pistons and rings, the output to the rotors would be 500-550 RPM's, I figured that off of the flywheel I would want about 3k RPM, Opinions?
When I cast I would use aluminum.
I am unfamiliar with aluminum, is there different grades of cast? can you temper it? does it shrink or expand after being cast? how much if so?

Thanks ETR

 

[tel]

Damn! So many questions, so little time. All I will say is that if I ever build something that will take me up in the air it WILL NOT be powered by a home cast engine. Messrs Volkswagen, having made several million of the things, have presumably accumulated far more expertise than I ever will, and I would be putting my faith in that. or someone like that!

 

[purpleknif]

Damn! So many questions, so little time. All I will say is that if I ever build something that will take me up in the air it WILL NOT be powered by a home cast engine. Messrs Volkswagen, having made several million of the things, have presumably accumulated far more expertise than I ever will, and I would be putting my faith in that. or someone like that!

Especially if its a "learning experience" !

 

[bearcar1]

Hello ETR and welcome to HMEM. If your intention is to use the cylinder 'jugs' from an existing full size engine for your project it will take a very large foundry setup to pour the crankcase housing and its various components. This is something that is not impossible but is usually out of the realm of the everyday hobbyist due to its size, fuel and materials costs. If you're going to use production parts as this, why not just use the entire engine for your purpose? VW engines have been used to good success for many years in the homebuilt aircraft circles for years. Now, the steam engine powering a generator may be subject to pursue here. Can you tell us where you are located and what machining experience back round you have, as these things will greatly influence any forthcoming suggestions.

cheers

BC1
Jim

 

[ericthered]

First off, why not buy a gasoline engine for the chopper? two reasons, Price, its a lot easier to justify greater expenses on a small scale than small expenses all at once, ie, 2-3k for engine, and probably around 2k to get setup to build one (el cheapo). convoluted logic but it works in my head. Reason number two, I have always wanted to be able to make my own parts for my vehicles... a lot easier to justify spending money to make something expensive than to make 50 cent parts.
That being said I would not think of rising a inch off of the ground without doing extensive testing, the first engine after being tested will not be used for the chopper, the second one will.
Regaring how hard it would be to cast it I recognize the problem, my solution is this, look at your air compressor, the cylindars (if you have a large one) are bolted to the crankcase, that would be the general design, that would do a couple of things, that would make it so you could cast the cylindars seperate from the block and make it so you could use the same castings for other applications.
As stated before, it would be air cooled, after casting it you would lathe the fins in, and hone the cylindars.
My machinist skills are as close to zero as you can get and still have a head on your shoulders. I have some small projects to do first to get the hang of it...
With the gas engine idea the chopper came first as a reason, with the steam the engine came before the generator application, my opinion is yeah its nice to watch a little flywheel spin madly about, but I prefer to have a reason to do something (even if its crazy).
ETR.
southern MT.

 

[ericthered]

-BUMP-

Any answers to my origional questions?
Thanks
ETR

 

[GWRdriver]

ETR,
I think it's probably because no one here wants to be implicated as having had a hand, however slight, in the event of your tragic and untimely demise. Seriously. There are reasons for the stringent mechanical requirements for manned flying machines and rather stiff penalties for not following them . . . with emphasis on the stiff.

 

[MachineTom]

I would suggest that look at the light helicopters at the local airport. Take some photos of the linkage to the rotor parts. Then buy your machines and try to make one or two of those parts to your own dimensions. This will begin to teach you the skills needed to make parts for a project on the scale you imagine. When you can do that so the parts are to size and fit and finish equal to the photos. Then begin to research what is needed to build a helicopter, materials, loads. designs etc.

I estimate that you could not build a helicopter for less than $100,000 in materials. And machines equal to that. I've spent $800 in materials for a steam engine that would fit in a box I could carry.

Igor Sikorski owned an aircraft factory and it took him 5 years to build the first heli.

 

[Ken I]

ETR,
I think it's probably because no one here wants to be implicated as having had a hand, however slight, in the event of your tragic and untimely demise.

I've been following this thread with concern.

Airworthiness rules and regulations vary but are generally pretty stringent concerning home built aircraft. You are normally required to register and submit to all sorts of inspections during the progress (I know in U.K. your resin storage needs to be approved just for instance) - welding must be done by registered aircraft welders - there must be part and material traceability etc. etc.

You cannot present a completed aircraft and request an inspection and clearance certificate (as you might do with a car).

I suggest you contact the relevant authorities and determine the "process" that needs to be followed - it will almost certainly be a grade "A" PITB.

All that aside - best of luck with your project and keep us posted.

Ken

P.S. your original question - Aluminium castings shrink (all castings shrink) - refer to a set of foundryman's tables for shrinkage allowances - you also get a "patternmakers rule" which is oversize with different scales for brass, aluminium, cast iron etc.

Refer to the "Home Foundry" & "Metal Casting Safety" sections of HMEM

 

[Troutsqueezer]

If I were considering designing and flying my own helicopter, I think I would start by obtaining degrees in materials science, mechanical and aeronautical engineering. Then maybe get some venture capitalists to back me, given the start up costs. Take some flying lessons. Hire a test pilot. Take out an insurance policy. Maybe you've done some of that, I dunno.

You get an "A" for thinking big. *beer*

 

[Tin Falcon]

Well ETR. You are not wrong for asking there are no dumb questions.
This is Home Model engine machinist. the emphasis here is on model engine building. A few have build lager engines to power somthing like a steam boat. Like others have said unless you have a degree in aeronautical engineering designing owes own is not advisable.

You wand to learn machining start with a simple wobbler.
Tin

 

[t_ottoboni]

IMHO the fist step of building yourself a helicopter would be to have some parachuting lessons... :

 

[1Kenny]

Hi ETR,

To answer your question. Start by reading and understanding FAR 33, Airworthiness Standards: Aircraft Engines.
http://ecfr.gpoaccess.gov/cgi/t/tex...rgn=div5&view=text&node=14:1.0.1.3.16&idno=14

Next, go to FAA:gov and click on Regulations and Policies. Know that area inside an out.

Next, you must contact the manager of your Flight Standards Distric Office so he can assign someone to your project.

You must use the standards listed in Advisory Circular 43.13.1B .

Hope this helps you get started.

Kenny

USA / FAA licensed Airframe & Powerplant Mechanic
FAA Safety Team Lead Representive
Home Model Engine Machinist Safety Moderator

 

[ericthered]

Thank you all for the replys, I will definately get more experience and learn more before venturing forth. Thank you for the link Kenny, I will use it and the info to much avail.
I will first get a grasp on machinning and reconsider my powerplant options... I am about as interested as the next guy as falling from the sky.
Thank you for your help and advice.
ETR

 

[90LX_Notch]

Just to get a "grasp" on machining will keep you very occupied for quite sometime. It's one thing to turn a part or mill it; it's a whole other thing to hold tight tolerances and produce the necessary fits required for an i.c. engine.